1
|
Kunzelman K, Reimink MS, Verrier ED, Cochran RP. Replacement of mitral valve posterior chordae tendineae with expanded polytetrafluoroethylene suture: a finite element study. J Card Surg 1996; 11:136-45; discussion 146. [PMID: 8811408 DOI: 10.1111/j.1540-8191.1996.tb00028.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND AND AIMS Expanded polytetrafluoroethylene (ePTFE) suture has been used clinically for replacement of ruptured mitral valve chordae tendineae. The purpose of this study was to assess mitral valve function after posterior chordal replacement with ePTFE suture. METHODS A three-dimensional finite element computer model of the mitral valve was used, which incorporated geometry, regional tissue thickness, collagen fiber orientation, and anisotropic material properties for the leaflets, interface, and chordae tendineae. To simulate chordal rupture, four marginal and four basal chordae were removed from the posterior leaflet. Chordal replacement was simulated using two elements with the physical and material properties of 2-0 ePTFE suture. Systolic loading pressures were applied. RESULTS The chordal rupture model demonstrated posterior leaflet prolapse, abnormal stress concentrations, potential regurgitation, and elevated chordal stress. Conversely, the chordal replacement model corrected the prolapse and returned chordal stress to normal levels. However, stress concentrations were shown at suture attachment points. CONCLUSIONS This integrated mitral valve finite element model provides a tool to investigate the performance of the valve system. In this study, we have shown that 2-0 ePTFE suture replacement of ruptured posterior chordae tendineae returns the valve to a near normal state, in terms of leaflet stress and coaptation, and chordal stresses.
Collapse
Affiliation(s)
- K Kunzelman
- Division of Cardiothoracic Surgery, University of Washington, Seattle 98195-6310, USA.
| | | | | | | |
Collapse
|
2
|
Abstract
The human mitral valve is the left atrio-ventricular valve which is composed of several components including leaflets, chordae tendineae, papillary muscles, and the valve annulus. Any or all of these components may fail and contribute to various valvular diseases including mitral regurgitation and mitral valve prolapse. A computer simulation of mitral valve mechanics and motion was written in BASIC for micro-computers. This program allows valvular geometry and biomechanical parameters to be varied and records time varying motion of the valve and all components during systole including a graphic display of the valve leaflets.
Collapse
Affiliation(s)
- G E Miller
- Bioengineering Program, Texas A & M University, College Station 77843-3131
| | | |
Collapse
|
3
|
Spodick DH, Doi YL, Bishop RL, Hashimoto T. Systolic time intervals reconsidered. Reevaluation of the preejection period: absence of relation to heart rate. Am J Cardiol 1984; 53:1667-70. [PMID: 6731312 DOI: 10.1016/0002-9149(84)90599-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Within limits, systolic time intervals are reliable reflectors of cardiac status and responses to physiologic and pharmacologic challenges, with various functional correlates. That heart rate (HR) is an important determinant of the duration of systole is well accepted, owing to its effect on left ventricular ejection time (LVET). An independent rate effect on preejection period (PEP) is disputed. Some studies in pooled normal subjects at rest showed some degree of HR-PEP covariance, leading to widespread rate correction in practical use. However, although right atrial pacing showed the expected HR-LVET relation, it consistently failed to show an HR-PEP relation. Systolic time intervals were examined from echocardiograms of a deliberately heterogeneous group comprising 50 consecutively appearing persons with sinus rhythm. There was no HR-PEP covariance (r = 0.23; p = not significant). However, our subjects were otherwise comparable to those of other investigators, in that all other relations in these subjects were as expected from studies in both pooled and paced subjects: HR with LVET (r = -0.74; p less than 0.001), PEP/LVET with ejection fraction (r = -0.85; p less than 0.001), and PEP/LVET with velocity of circumferential fiber shortening (r = -0.65, p less than 0.001). Thus, HR correction of PEP is inappropriate. All other relations are substantiated in routinely encountered, unselected subjects.
Collapse
|
4
|
Thomas J, Fouad FM, Tarazi RC, Bravo EL. Evaluation of plasma catecholamines in humans. Correlation of resting levels with cardiac responses to beta-blocking and sympatholytic drugs. Hypertension 1983; 5:858-63. [PMID: 6140220 DOI: 10.1161/01.hyp.5.6.858] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The changes in systolic time intervals (STI) following reduction of adrenergic activity was used to validate supine resting plasma catecholamines (CATs) as an index of sympathetic activity. Blockade of sympathetic activity was achieved by two means in two groups: propranolol (10 mg i.v.) and clonidine (0.3 mg p.o.). The diminished sympathetic effect was evidenced by slowing (p less than 0.01) of heart rate with both drugs and the reduction (p less than 0.01) of blood pressure with clonidine. There was no correlation in our study between resting plasma CATs (norepinephrine alone or total), and changes in heart rate and preejection period (PEP). Moreover, to avoid changes in PEP that could be related to differences in blood pressure levels (clonidine-reduced blood pressure while propranolol did not), the changes in PEP were corrected for the change of mean arterial pressure (MAP) in the same patients (delta PEP/(delta MAP and % delta PEP/% delta MAP). No correlation could be found, still, between resting supine plasma CATs and these ratios. The difficulty in demonstrating a correlation between resting plasma CATs and the immediate cardiac response to adrenolytic agents can be explained by the number of factors influencing plasma levels. Circulating plasma CATs represent the spillover from adrenergic nerve endings, and, therefore, their level would depend on several factors including sympathetic nervous system activity, rate of reuptake, and rate of degradation.
Collapse
|
5
|
Espolita Santos J, Lopez-negrete Fernandez J, Fernandez Bustillo E, Lopez de la Iglesia J, Enriquez Martin J, Iglesias Cubero G, Tomas Mauri J, Rodriguez Reguero J, Soriano Vela E. Intervalos sistolicos. Relacion PPE/PE en el cor pulmonale cronico. Arch Bronconeumol 1983. [DOI: 10.1016/s0300-2896(15)32305-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
6
|
Mertens HM, Mannebach H, Trieb G, Gleichmann U. Influence of heart rate on systolic time intervals: effects of atrial pacing versus dynamic exercise. Clin Cardiol 1981; 4:22-7. [PMID: 7226587 DOI: 10.1002/clc.4960040106] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The effects of atrial pacing and dynamic exercise in the supine position on systolic time intervals (STI) were compared in 10 normals. In another group of 13 normals, the effect of exercise alone on STI was tested. A linear shortening of electromechanical systole (QS2) and left ventricular ejection time (LVET) with increasing heart rate was demonstrated with right atrial pacing and dynamic exercise in the frequency range between 60 and 140 beats/min. However, the shortening of LVET was significantly less (p less than 0.01) with exercise compared to pacing. This is explained by an increase in left ventricular stroke volume with exercise. The preejection period (PEP) was significantly (p less than 0.001) shortened with exercise, but there was no change with atrial pacing. Thus, changes in heart rate (HR) alone, without changes in the dynamic state of the heart, did not influence PEP. It is suggested that PEP at rest should not be corrected for heart rate. The supine exercise regression equations for correction of heart rate for LVET and PEP differ from both the resting and the upright exercise regression equations. With exercise a frequency correction of STI using regression equations should be abandoned. Instead, uncorrected STI at standard heart rates (e.g., 100, 110, and 130 beats/min) should be taken for comparison. Heart rate standardization should be employed using the formula: Formula (See Text).
Collapse
|
7
|
Abstract
Isovolumic relaxation period (IRP) was measured noninvasively from the onset of the aortic component of the second heart sound on the phonocardiogram to the point of separation of the mitral leaflets on the echocardiogram. IRP was measured in 83 patients with different cardiac diseases. The duration of IRP was 58 +/- 11 msec. in normal subjects. It was prolonged in hypertension (p < 0.001), HOCM (p < 0.001), in aortic stenosis (p < 0.05), and aortic incompetence (p < 0.001), and was shortened in congestive cardiomyopathyl (p < 0.05) and mitral stenosis (p < 0.01). In patients with coronary artery disease and normal over-all systolic LV function, IRP was prolonged (p < 0.001); IRP was shortened in four patients with coronary disease who had severe LV dysfunction and severe additional mitral incompetence. IRP was related to systemic blood pressure, percentage shortening of the LV in systole, and to the mitral EF slope. It tended to increase with increasing heart rate and a regression equation was developed for predicting IRP in relation to blood pressure and heart rate in normal sbjects. There was no relation to the PR-Ac time or to isovolumic contraction time. IRP is a useful measurement of LV dynamics in early diastole.
Collapse
|
8
|
Light KC, Obrist PA. Cardiovascular response to stress: effects of opportunity to avoid, shock experience, and performance feedback. Psychophysiology 1980; 17:243-52. [PMID: 7384374 DOI: 10.1111/j.1469-8986.1980.tb00143.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
|
9
|
|
10
|
|
11
|
Lewis BS, Rachmilewitz EA, Amitai N, Halon DA, Gotsman MS. Left ventricular function in beta-thalassemia and the effect of multiple transfusions. Am Heart J 1978; 96:636-45. [PMID: 162523 DOI: 10.1016/0002-8703(78)90201-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Left ventricular performance was studied in 23 young patients with severe chronic anemia due to beta-thalassemia major and intermedia. The patients were divided into three groups according to the number of blood transfusions they had received. The left ventricle (LV) was enlarged in patients who had not received blood and larger still in patients who had received multiple transfusions. Echocardiography and systolic time interval measurements showed that systolic function of the LV was good in all the patients and that there was no statistical difference in systolic function in patients who had and those who had not received multiple transfusions. Heart rate was increased in the latter group. Stroke index and cardiac index were high, especially in patients in Group 3. The diastolic closure rate (EF slope) of the anterior mitral leaflet and its amplitude of movement were increased, but less so in Group 3; this may reflect an alteration in diastolic LV distensibility. The results indicate that despite the presence of cardiomegaly and severe clinical congestive heart failure, LV performance is well preserved in patients with beta-thalassemia, even in those who have received repeated blood transfusions. Clinical cardiac failure is the consequence of volume overload and abnormal chamber compliance. There was no evidence in this of a congestive cardiomyopathy.
Collapse
|
12
|
Cousineau D, Lapointe L, de Champlain J. Circulating catecholamines and systolic time intervals in normotensive and hypertensive patients with and without left ventricular hypertrophy. Am Heart J 1978; 96:227-34. [PMID: 150222 DOI: 10.1016/0002-8703(78)90090-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
13
|
|
14
|
Reeves WC, Nanda NC, Gramiak R. Echocardiography in chronic alcoholics following prolonged periods of abstinence. Am Heart J 1978; 95:578-83. [PMID: 636999 DOI: 10.1016/0002-8703(78)90299-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
15
|
Wikstrand J, Berglund G, Wilhelmsen L, Wallentin I. Value of systolic and diastolic time intervals. Studies in normotensive and hypertensive 50-year-old men and in patients after myocardial infarction. Heart 1978; 40:256-67. [PMID: 637979 PMCID: PMC481990 DOI: 10.1136/hrt.40.3.256] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
|
16
|
Balasubramanian V, Mathew OP, Tiwari SC, Behl A, Sharma SC, Hoon RS. Alterations in left ventricular function in normal man on exposure to high altitude (3658 m). Heart 1978; 40:276-85. [PMID: 637981 PMCID: PMC481992 DOI: 10.1136/hrt.40.3.276] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
|
17
|
Araoye MA, Rubler S, Holford FD. Isovolumic relaxation time in normal subjects and patients with cardiac disease: comparison of determinations made with echocardiographic techniques and apex cardiography. Angiology 1978; 29:7-15. [PMID: 629424 DOI: 10.1177/000331977802900102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Isovolumic relaxation time (IVRT) was determined in 17 controls and 41 patients. Nine patients had ischemic heart disease (IHD), 7 mitral prolapse (MVPS), 13 hypertension (HPB), 7 pregnancy (P), and 5 cardiomyopathy (CM). Echocardiographic measurements of IVRT were made from the aortic second sound to the rapid opening of the mitral valve (A2D1). Determinations by apexcardiography were made from the aortic second sound to the 0 point (A2O). The IVRT was distinctly shorter when assessed by A2D1 than by conventional apexdardiography in conventional apexcardiography in controls (69.2 +/- 16.4 msec vs 118.7 +/- 16.5 msec) and in patients with cardiac disease. The IVRT in 9 older normal controls (mean age 47.7 years) was longer than in 8 younger ones (age 26.3 +/- 4.9 years). Patients with myocardial disease (IHD, HBP, and CM) had prolonged IVRTs when compared to normal subjects. Pregnant subjects had shortened intervals. IVRT may be a sensitive indicator of disturbances in myocardial contractility and may be shortened and enhanced contractility.
Collapse
|
18
|
Gould L, Reddy CV, Chua W, Swamy CR, Dorismond JC. Fibroplastic parietal endocarditis with eosinophilia. Angiology 1977; 28:779-87. [PMID: 143901 DOI: 10.1177/000331977702801107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A 44-year-old woman with marked eosinophilia, leukocytosis, congestive heart failure, and the murmur of mitral stenosis had a restrictive type of pulse contour at cardiac catheterization. A right atrial angiogram revealed a huge right atrium, a small right ventricle, and a dilated contractile outflow tract consistent with the diagnosis of Loeffler's endocarditis. A marked conduction delay at the atrial level was demonstrated by His bundle electrogram studies.
Collapse
|
19
|
Roland EQ, Safar ME, Lelguen CE, Aboras NE, Weiss YA, Milliez PM. Effect of certain antiadrenergic agents on systolic time intervals in essential hypertension. Eur J Clin Pharmacol 1977; 11:423-7. [PMID: 891585 DOI: 10.1007/bf00562932] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Systolic time intervals, including preejection period (PEP) and left ventricular ejection time (LVET), were studied in patients with permanent essential hypertension before and after intra-venous administration of propranolol 0.2 mg/kg (11 patients), clonidine 0.002 mg/kg (10 patients) and methyldopa 2 mg/kg (12 patients). With propranolol, diastolic blood pressure was unchanged and the heart rate decreased, whilst PEP and LVET were significantly prolonged (P less than 0.001). Clonidine caused a fall in blood pressure (P less than 0.001), heart rate was slightly reduced, PEP was prolonged (P less than 0.001) and there was a significant decrease in LVET at 5 min. With methyldopa, no significant effect was observed after intravenous injection, but 7 days oral administration produced the identical effect as clonidine. These observations suggest that certain antihypertensive drugs may impair left ventricular performance and depress myocardial contractility.
Collapse
|
20
|
Abstract
Twenty-two cases of Coxsackie virus heart disease diagnosed from November, 1969, to December, 1971, were re-examined after a period of 42 to 68 months from the acute illness. The patients with hypertension, diabetes, chronic alcohol intake, or aged over 35 were eliminated from the trial. With the purpose of assessing myocardial function, the systolic time intervals were recorded by a noninvasive standard technique. The differences in systolic time intervals between the group of patients with previous viral myocarditis and a group of normal control subjects were not statistically significant. However, the pre-ejection period was clearly prolonged in three patients out of 10, a modification consistent with a depressed myocardial function, as in patients with cardiomyopathy.
Collapse
|
21
|
Abstract
Externally recorded STI were compared with invasively determined EF in 10 normal subjects and 86 patients with various forms of chronic heart disease. From phono-, apex-, and electrocardiograms and carotid pulse tracings, recorded without rigidly controlled conditions (postabsorptive state, fixed time of day, exclusion of atrial fibrillation, and discontinuation of cardiac drugs), PEP, electromechanical interval, isovolumic contraction period, and LVET were measured and deltaPEP (deviation from predicted normal) and PEP/LVET were drived. EF was determined with biplane angiocardiographic methods. Patients were divided into groups based on pathophysiology and state of clinical compensation. The ability of STI to discriminate abnormal from normal function, as compared with EF, varied with each noninvasive parameter and with each physiologic group. On a group basis, the discriminatory ability of PEP was better than that of other noninvasive parameters studied, but did not always parallel that of EF. PEP also tended to correlate better with EF than the other noninvasive measurements. On an individual patient basis, however, the ability of even PEP to predict EF was poor. It is concluded that the usefulness of assessing left ventricle function in chronic heart disease by STI is limited.
Collapse
|
22
|
Divers RT, Katona PG, Dauchot PJ, Hung JC. Continuous real-time computation and display of systolic time intervals from surgical patients. COMPUTERS AND BIOMEDICAL RESEARCH, AN INTERNATIONAL JOURNAL 1977; 10:45-59. [PMID: 858229 DOI: 10.1016/0010-4809(77)90050-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
23
|
|
24
|
Abstract
Left ventricular function was studied in 14 patients with end-stage chronic renal failure using non-invasive methods (echocardiography and systolic time intervals). Patients were divided into 3 groups. Group 1 consisted of 5 patients who were normotensive at the time of study and group 2 of 7 patients who were hypertensive when studied. Group 3 consisted of 2 patients: one was receiving propranolol and the other, studied 302 days after renal transplantation, was receiving digitalis for recurrent episodes of cardiac failure. All except the patient receiving propranolol had normal left ventricular function in systole with normal measurements of fractional fibre shortening (% delta S, EF) and normal measurements relating to the velocity of ventricular contraction (mean Vcf, mean velocity of posterior wall motion). Stroke volume and cardiac output were normal in some patients but were increased in patients with fluid overload. Early diastolic compliance of the left ventricle seemed to be normal except in the patient with recurrent cardiac failure. The study provided no evidence for the existence of a specific uraemic cardiomyopathy.
Collapse
|
25
|
Haraphongse M, E. Basualdo CA, Fraser RS, Rossall RE. The assessment of function of left ventricle and patency of aorta-coronary bypass after operation. J Thorac Cardiovasc Surg 1976. [DOI: 10.1016/s0022-5223(19)40450-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
26
|
Berk S, Kino M, Spodick DH. Noninvasive differentiation of cardiomyopathy from coronary disease; pulse transmission time and systolic time intervals. J Am Geriatr Soc 1976; 24:289-91. [PMID: 932377 DOI: 10.1111/j.1532-5415.1976.tb06798.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Systolic time intervals and central pulse transmission time were compared in cardiomyopathy (CM) patients and age-and sex-matched patients with coronary artery disease (CAD). Significant differences were found in pulse transmission time (shorter in the CAD patients (p less than .001) and in the pre-ejection period (p less than .001), ejection time index (p less than .05), and in the ratio of the pre-ejection period to the left ventricular ejection time (p less than .001); all were markedly abnormal in the CM group. Pulse transmission time differences may have been the result of more generalized arteriosclerotic disease in the CAD patients. It appears that both systolic time intervals and pulse transmission time clearly distinguish CM from CAD.
Collapse
|
27
|
Curtiss EI, Reddy PS, O'Toole JD, Shaver JA. Alterations of right ventricular systolic time intervals by chronic pressure and volume overloading. Circulation 1976; 53:997-1003. [PMID: 1269138 DOI: 10.1161/01.cir.53.6.997] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Right ventricular (RV) systolic time intervals and hemodynamic parameters were determined by micromanometric techniques in 13 subjects with normal right ventricles (NRV). These data were compared to those of 16 patients with pulmonary hypertension (PH) or predominant pressure overloading and 13 individuals with uncomplicated secundum atrial septal defects (ASD) or predominant volume overloading. In PH, the QP2 interval tends to remain within the normal range due to reciprocal changes in isovolumic contraction (ICT) and ejection (RVET) times. Elevations of pulmonary artery diastolic pressure are associated with increases in the mean rate of isovolumic pressure rise (MRIPR) (r = 0.84), but the latter change does not fully compensate for the widened ventriculoarterial diastolic pressure difference and ICT becomes prolonged (P less than 0.001). Factors other than stroke index depression which may contribute to the decreased duration of RVET (P less than 0.001) include tricuspid regurgitation and elevation of pulmonary vascular impedance. In ASD, QP2 is significantly prolonged (P less than 0.025) due to a significant increase in RVET (P less than 0.005). In contrast to NRV, a linear correlation of RVET and stroke index was not present, which suggested an alteration of ejection dynamics in this group. Despite a high incidence of complete or incomplete right bundle branch block the interval from QRS onset to rapid RV pressure upstroke was not prolonged. This is most probably the result of peripheral bundle branch block of genesis of the QRS pattern by right ventricular hypertrophy.
Collapse
|
28
|
Tarazi RC, Ibrahim MM, Dustan HP, Bravo EL. Use of systolic time intervals in studying hypertension. AUSTRALIAN AND NEW ZEALAND JOURNAL OF MEDICINE 1976; 6 suppl 2:8-14. [PMID: 1067829 DOI: 10.1111/j.1445-5994.1976.tb03317.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Systolic time intervals were measured in 54 hypertensive patients divided into three groups according to severity of hypertension, variability of blood pressure levels and presence or absence of a hyperkinetic heart. The three groups were: borderline hypertension (BLH), fixed essential hypertension (FEH) and hyperkinetic essential hypertension (HEH). Systolic time intervals (STI) provided information indicating an increased cardioadrenergic drive in BLH and HEH. This was supported by finding that propranolol abolished the increased contractility found at rest in BLH and HEH.
Collapse
|
29
|
Abstract
The systolic time intervals; total electro-mechanical systole (QS2), left ventricular ejection time (LVET), pre-ejection period (PEP), and ratio of PEP/LVET were measured from external readings in twenty hyperthyroid and fifteen hypothyroid patients. The hyperthyroid subjects showed shortening of the PEP and reduction in the PEP/LVET. The hypothyroid group showed lengthening of the PEP, shortening of the LVET and increased PEP/LVET. These changes returned towards normal in ten patients rendered euthyroid with appropriate therapy. The value of these measurements to predict the thyroid status was examined in a mixed group of seventy-four patients. There was close agreement between diagnosis predicted from systolic time intervals and that made independently from clinical and biochemical assessment, suggesting that the systolic time intervals may have been a useful place in the clinical assessment of thyroid patients.
Collapse
|
30
|
D'Angelo R, Shah N, Rubler S. Diastolic time intervals in ischemic and hypertensive heart disease: A comparison of isovolumic relaxation time and rapid filling time with systolic time intervals. Chest 1975; 68:56-61. [PMID: 1149531 DOI: 10.1378/chest.68.1.56] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Isovolumic relaxation time (IVRT) and rapid filling time (RFT) were used to evaluate elasticity and compliance in 11 control subjects (Group 1), in nine patients with angina (Group 2), in 11 with hypertensive heasrt disease (Group 3), and in ten patients with healed myocardial infarction (Group 4). Pre-ejection period (PEP), pre-ejection period index (PEPI), left ventricular ejection time (LVET), left ventricular ejection time index(LVETI) and PEP/LVET ratio were all derived from simultaneous recordings of phonocardiograms, ECGs, apexcardiograms, and external carotid arterial pulses. No patients were in congestive heart failure and none were receiving medication. LVET and LVETI were the same in control patient groups; PEP was slightly increased in patients with healed myocardial infarctions (p smaller than 0.05); and PEPI was prolonged in the patients with angina (p = 0.001). THE PEP/LVET ratio too was different from the control group in patients with angina and hypertension (Groups 2 and 3-p smaller than 0.02 and smaller than 0.05 respectively). The diastolic time intervals were significantly altered in that the IVRT was prolonged in angina patients (113.4 equals or minus 28.3 msec), compared to control patients (85.7) equal or minus 18.4 msec). It was found that in 6 out of 9 patients with angina, this interval exceeded the highest normal value (108 msec), but that in only one out 11 patients with HCVD and in three out of ten with healed infarctions, was the interval prolonged. RFT was increased in HCVD (113.8 equals or minus 18.8 msec) and in healed myocardial infarction (123.8 equals or minus 30.0 msec) patients, compared to the control group (94.5 equals or minus 12.8 msec). Diastolic time intervals reflecting disorders in elasticity and compliance may occur in conjunction with alterations in systolic time intervals.
Collapse
|
31
|
Xenakis AP, Quarry VM, Spodick DH. Immediate cardiac response to exercise: physiologic investigation by systolic time intervals at graded work loads. Am Heart J 1975; 89:178-85. [PMID: 1114945 DOI: 10.1016/0002-8703(75)90043-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Immediate cardiac responses to exercise were investigated in five normal male volunteer subjects by measuring heart rate and systolic intervals from rest through the onset of exertion at three different work loads. Recordings were continued for fifty beats and again at one minute with measurements plotted on a beat-to-beat basis and grouped for statistical analysis. During exercise, heart rate and corrected ejection time increased, pre-ejection period and PEP/LVET decreased, and pulse transmission time remained stable. The heart rate acceleration was sudden, occurring in the first few beats of exercise, a phenomenon also demonstrated by previous investigators. A significant new finding was the equally abrupt major change in each of the other parameters. The immediacy of all responses was independent of load and was consistent with experimental studies showing that changes in both neural activity and venous return at the onset of exercise are virtually instantaneous.
Collapse
|
32
|
|
33
|
Zoneraich S, Zoneraich O, Rodenrys J. Computerized system for noninvasive techniques. 1. Its value for systolic time intervals. Am J Cardiol 1974; 33:643-9. [PMID: 4595160 DOI: 10.1016/0002-9149(74)90256-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
34
|
Zambrano SS, Mazzotta JF, Sherman D, Spodick DH. Cardiac dysfunction in unselected chronic alcoholic patients: noninvasive screening by systolic time intervals. Am Heart J 1974; 87:318-20. [PMID: 4812369 DOI: 10.1016/0002-8703(74)90072-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
35
|
Maher JT, Beller GA, Ransil BJ, Hartley LH. Systolic time intervals during submaximal and maximal exercise in man. Am Heart J 1974; 87:334-42. [PMID: 4812371 DOI: 10.1016/0002-8703(74)90075-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
36
|
|
37
|
Lewis BS, Armstrong TG, Everson RC, Gotsman MS. Predictive value of the systolic time intervals in primary myocardial disease. Chest 1973; 64:431-8. [PMID: 4743949 DOI: 10.1378/chest.64.4.431] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
|
38
|
|
39
|
Ibrahim M, Silie M, Delahaye JP, Froment R. Systolic time intervals in valvular aortic stenosis and idiopathic hypertrophic subaortic stenosis. BRITISH HEART JOURNAL 1973; 35:276-83. [PMID: 4734998 PMCID: PMC458601 DOI: 10.1136/hrt.35.3.276] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
40
|
Lindquist VA, Spangler RD, Blount SG. A comparison between the effects of dynamic and isometric exercise as evaluated by the systolic time intervals in normal man. Am Heart J 1973; 85:227-36. [PMID: 4688832 DOI: 10.1016/0002-8703(73)90464-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
41
|
Spodick DH, Pigott VM, Chirife R. Preclinical cardiac malfunction in chronic alcoholism. Comparison with matched normal controls and with alcoholic cardiomyopathy. N Engl J Med 1972; 287:677-80. [PMID: 5055416 DOI: 10.1056/nejm197210052871401] [Citation(s) in RCA: 136] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
42
|
Austin TW, Ahuja SP, Boughner DR. Atraumatic study of left ventricular events following acute myocardial infarction. Am J Cardiol 1972; 29:745-8. [PMID: 5033719 DOI: 10.1016/0002-9149(72)90491-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
43
|
Chirife R, Spodick DH. Densitography: a new method for evaluation of cardiac performance at rest and during exercise. Am Heart J 1972; 83:493-503. [PMID: 5041837 DOI: 10.1016/0002-8703(72)90040-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
44
|
McConahay DR, Martin CM, Cheitlin MD. Resting and exercise systolic time intervals. Correlations with ventricular performance in patients with coronary artery disease. Circulation 1972; 45:592-601. [PMID: 5012247 DOI: 10.1161/01.cir.45.3.592] [Citation(s) in RCA: 49] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Indirect systolic time intervals (STI) corrected for heart rate were compared at rest and immediately following 3 minutes of moderate supine exercise in 33 normal subjects and 32 age- and sex-matched patients with coronary artery disease (CAD). The intervals were correlated with measurements of cardiac index (CI), stroke volume index (SVI), mean pulmonary artery and wedge pressures obtained under identical conditions of rest and exercise, and with resting left ventricular end-diastolic pressure (LVEDP), LV dp/dt, exercise factor, ejection fraction (EF), and extent of CAD.
Total electromechanical systole (Q-A2
c
) was the same at rest in both normal and CAD groups and did not change with exercise in either group. The CAD group had a significantly longer preejection period PEP
c
), shorter left ventricular ejection time (LVET
c
), and larger PEP/LVET at rest and exercise than the normal group. Both groups responded to exercise with a significant reduction of PEP
c
, prolongation of LVET
c
, and reduction of PEP/LVET. Significant correlations were found between these STI and SVI, CI, LV dp/dt, LVEDP, and EF, which explained the differences in STI between the normal and CAD groups. However, exercise did not improve the sensitivities of the STI in detecting disordered hemodynamics in the patients with CAD. Furthermore, the STI failed to predict reliably hemodynamic abnormalities in the individual patient which were not already clinically obvious.
Collapse
|
45
|
Dowling JT, Sloman G, Urquhart C. Systolic time interval fluctuations produced by acute myocardial infarction. BRITISH HEART JOURNAL 1971; 33:765-72. [PMID: 5115022 PMCID: PMC487249 DOI: 10.1136/hrt.33.5.765] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
46
|
Martin CE, Shaver JA, Thompson ME, Reddy PS, Leonard JJ. Direct correlation of external systolic time intervals with internal indices of left ventricular function in man. Circulation 1971; 44:419-31. [PMID: 5097444 DOI: 10.1161/01.cir.44.3.419] [Citation(s) in RCA: 141] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Direct correlation of externally measured systolic time intervals with internally measured indices was obtained using catheter-tip micromanometers in six patients who had normal coronary arteriograms. Simultaneous recordings were made of central aorta and left ventricular pressure, maximum rate of rise in left ventricular pressure (dp/dt), external carotid pulse, external and internal sound, and electrocardiogram. Acute interventions were used to vary the indices by a variety of mechanisms including changes in contractility, preload, afterload, and heart rate. The initial values and the changes in these values produced by acute interventions are identical for left ventricular ejection time (LVET) whether measured externally (range 175 to 385 msec) or internally (range 169 to 392), r = 0.99. Although the absolute values differed for internally measured isovolumic contraction time (internal ICT), externally measured ICT, and preejection time (PEP), there was good linear correlation between the changes observed in these values following the interventions. Changes in PEP and internal ICT showed excellent linear correlation (r = 0.94) and were also alike in absolute value following the interventions. The interval from the Q wave of the electrocardiogram to rise in left ventricular pressure (electrical-mechanical delay) did not change significantly during these interventions. During a period of spontaneous isorhythmic dissociation there was close tracking between beat-to-beat changes in PEP and internal ICT and between externally and internally measured LVET. Following acute interventions PEP and left ventricular dp/dt changed inversely.
Externally measured systolic time intervals have therefore been shown in man to correlate well with directly measured internal indices, both in steady-state conditions and during a series of acute interventions. This convenient and atraumatic method has been shown to be a valid and sensitive measure of myocardial performance.
Collapse
|
47
|
|
48
|
Büyüköztürk K, Kimbiris D, Segal BL. Systolic time intervals. Relation to severity of coronary artery disease, intercoronary collateralization and left ventricular dyskinesia. Am J Cardiol 1971; 28:183-90. [PMID: 5560826 DOI: 10.1016/0002-9149(71)90368-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|